Do telephone calls have the best UX?
- Type in a number
- Press "Call"
- They receive a request
- If accepted, a voice channel is opened
- Either party can press "end"
Well, there is the underlying tension between the interest of the caller, who wishes to be heard immediately, and the receiver, who will have to drop everything to pay attention to the caller.
In a sense, email is more respectful of people's attention by being something they have to check in their own time, although notifications have spoiled that.
I guess if that's the end-to-end model of what a call is, then yes by definition it's very clean and sweet. But if not--it really depends...did my cheek or ear hang up the call due to some OS feature, did my bluetooth work, in what position did I need to place the phone, and so on...
Better UX would be being able to tell before answering if the number is spoofed or not - or a known spammer.